Evaluation of a universal real-time polymerase chain reaction for detection of amniotic fluid infection in premature rupture of membranes

Managing preterm rupture of membranes (PPROM) is a balance between benefits of prolonging gestation and the risks of perinatal infection. This study evaluates a real-time polymerase chain reaction (PCR) for the detection of amniotic fluid infection and neonatal complications by amniocentesis following PPROM. A total of 61 singleton pregnancies with PPROM were analyzed retrospectively, including histopathologic examination of the placenta and neonatal complications. The real-time PCR detects a highly conserved sequence of the bacterial 16S ribosomal DNA, and its efficacy was compared with standard tests including amniotic fluid glucose concentration, lactate dehydrogenase level, and maternal white cells count and C-reactive protein levels. Sensitivity and specificity were similar for PCR (64% and 85%) and standard tests (58% and 80%). However, the PCR technique has the additional advantage of possible identification of the bacteria through sequencing and has a much better positive predictive value in the occurrence of neonatal complications (60% for PCR versus 35% for standard tests). The latency period between premature rupture of the membranes and delivery was not related to the incidence of histopathologic signs of infection in the placenta or the umbilical cord and was inversely related to the incidence of neonatal complications.